Minerality Lacks An Objective Meaning

Scott Rich, the proprietor (along with his spouse Marta) and winemaker of Talisman Wines in Sonoma, California, has me thinking about one of the most perplexing words in common wine parlance: minerality. I have also read a number of commentaries about minerality written by prominent wine writers of late. It seems like the more we know, the less we know about minerality, despite its common usage as a wine descriptor in wine reviews and discussions of terroir.

Examples of mineral-based terminology abound. A recent review of 2012 Domaine Leflaive Batard Montrachet by Stephen Tanzer described the wine as “Quite full, rich and powerful, with a distinctly tactile quality to the saline, iodine and mineral flavors.” In another review by Tanzer of the 2012 Domaine Leflaive Chevalier Montrachet, he describes “a pungent vein of stony minerality running through the wine,” and refers to the wine’s “mineral tension.” The Burghound often mentions “mineral-inflected flavors” in his reviews of white Burgundy. Wine Spectator refers to “mineral aromas and flavors” and “a long aftertaste of stone” in a recent review of the 2011 Domaine Leflaive Puligny Clavoillon.

The use of the word mineral in all its forms seems to be confined almost solely to white wines. For example, a Buying Guide from the Wine Enthusiast that included reviews of white and red Burgundy wines primarily from the 2010 vintage, had fifteen references to minerality among the white wine reviews and only two mentions of minerality among the more numerous red wine reviews. Until we can state for certainty what minerality in wine is, and are able to use science-based descriptors rather than general terms like “mineral aromas and flavors,” perhaps we should refrain from using the ambiguous word “mineral” altogether.

Scott makes some astute points which I quote and paraphrase here. He says, “Much of the discussion about minerality has amused me because no one seems to be addressing the most obvious issue. That is, the term must be defined through standards so everyone is talking about the same thing, just like in the use of any other wine descriptor.” Scott, like many others of scientific leaning, wants a concrete (sic) definition of minerality established by standards that the wine community can agree upon.

Noted winemaker and wine researcher, Clark Smith, thinks it is ‘indefinable,’ but attributes minerality to an ‘energetic buzz.’ Others think its not worth the effort to define, saying it is all bullshit. Robert Joseph wrote satirically (timatkin.com November 18, 2013), “Any scientist will tell you that there’s no granite or chalk in that wine. You ask a hundred people whether they want a mineral wine and there’s probably only two or three who’ve any idea what you’re talkin’ about.”

Attempts to define minerality have led to widely diverse opinions. I would liken it to pornography: you can’t define it but you know it when you experience it. Scott notes that some perceive it as a ‘bright’ feeling in a wine, something some French tasters describe as ‘energetic.’ Others describe it as an aroma attribute, such as the smell of wet granite after a rain, and we all are familiar that smell, correct? It is also a general phrase that is used to describe wines that are not fruity, spicy or herbal. All that means, as Scott jokingly points out, is that the wine isn’t fruity, spice or herbal and the lack of these attributes does not by inference mean the wine has minerality. There are those who associate minerality with high acidity, but we know wines that are not high in acidity can seem to have minerality. Some have attributed minerality to volatile sulfur compounds in wine, also known as ‘reduction.’ Finally, people have used minerality to describe a mouthfeel or sensation, and although minerality may include this idea, that cannot be all there is to it.

Here are some definitions of minerality that I have heard or read in the past few years:

“A descriptor that reflects our struggle to find what we are experiencing.” Winemaker James Cahill

“An effort to connect wine to the place it is grown.” Winemaker Fintan du Fresne

“A way to describe the non-fruit components of wine. A word used to describe what one can’t describe plainly.” Winemaker Jason Jardine

“A lack of fruit character in wine.” Winemaker Mike Waller.

“A soil-based characteristic in wine.” Winemaker Jason Jardine.

“I think of minerality as a wet-stone quality in a wine.” Winemaker Paul Draper.

“The perception of geology in wine.” Dr. James Kennedy, California State University at Fresno

“Something that exists but is not explainable. I know it when I taste it.” Writer Karen MacNeil.

“Minerality is a complex mixture of compounds in wine which we associate with the smell of soils or rocky area.” Scientist Dr. Sue Ebeler, UC Davis.

“Minerality is being able to actually taste the vineyard geology in the wine....in any literal way is scientifically impossible. Whatever minerality is, it is not the taste of vineyard minerals.” Alex Maltman, Institute of Geography and Earth Science, Wales. (see below for further discussion by Alex Maltman)

“I can’t define minerality, but I know it when I feel it.” Writer Steve Heimoff.

”I suppose it is easier to define what it is not - that is, it is not fruit, nor acidity, nor tannins, nor oak, nor richness, nor fleshiness. It is not really a texture, either, for texture is in the middle of the palate and minerality is at the end. I think it is just there, a sort of lifted and lively stoniness that brings a sense of grip and a sense of depth, but it is neither grippy (which is tannin) nor deep (which is fruity).” Writer Stephen Spurrier (to Jamie Goode in The Science of Wine.

“Wines richer in minerals present way differently. There is a suppression of obvious fruit....the wines seem to have a sort of nucleus or density around their ether. They are gathered, focused, cohered the way a laser coheres light.” Winemaker Randall Grahm.

“Minerality is a concept which could never be consistently defined in words or physical standards.” Sensory chemist Dr. Ann Noble.

“The minerality of a wine is experienced like a generation of tension in the mouth that is innately refreshing and energizing.” Winemaker Jason Lett.

“Minerality is more of a sensation than a flavor that predominantly appears in an elusive finish.” Winemaker Steve Matthiasson.

“Minerality is the aroma, taste and tactile sensation in wine when grapes are grown on rocks.” Winegrower Kevin Harvey.

“Minerality or mineral-driven wines are those that are not highlighted by oak regimen or fruitiness but by soil flavors and stoniness. When it applies to white wines, it means low alcohol, high acid and freshness.” Sommelier Mike Madrigale (The SOMM Journal Aug/Sept 2014).

“Minerality to me is non-fruit and non-oak descriptors for a wine - things like chalk, crushed seashells, gravel, gun flint, a sidewalk after a light rain. I feel like when people run out of descriptors for a wine, after they’ve named all the fruit and herbs, they often say “minerality’ instead of really defining what that minerality is.” Sommelier Jeff Taylor (The SOMM Journal Aug/Sept 2014).

“Minerality is one of the more important components of a great wine. That said, it is one of the more difficult terms to define. To me, wine with a lifted finish, bright acidity and a notion of saltiness can be said to possess minerality. Beyond that, a difficult-to-pinpoint characteristic of great ‘drinkability’ always goes hand-in-hand with wines of minerality. We, as an industry, need to pinpoint the important aspects of (it) and share it with our guests.” Sommelier Eduardo Port Carreiro (The SOMM Journal Aug/Sept 2014).

“Minerality is a fashionable word never employed in the 1970s and 1980s. The only no-nonsense use is to describe a wine marked by salty and mineral undertones balancing the fruit, more often a white wine rich in calcium and magnesium as many mineral waters are. For a red wine I have no idea.” Writer Michael Bettane (to Jamie Goode in The Science of Wine).

“Minerality, although a useful term for conveying suggestions of flavors, textures and aromas, should not be taken literally. As several geologists have stressed to me, vine roots simply are incapable of extracting aromatic compounds from hard rock, let alone transporting them directly to grapes. That’s just not the way plants grow, despite romantic wine geek notions to the contrary. The mineral content in wine is well below the threshold of human perception. Stone in wine? It’s blarney.” Writer Beppi Crosariol (The Globe and Mail, Canada, online).

“While the concept of minerality should not be taken literally in trying to analyze, quantify and scientifically explain a wine’s character and quality, the terms and its related forms such as ‘stony,’ flinty,’ ‘chalky,’ etc., remain valid and at times very useful words in the winetaster’s lexicon.” Writer Stephen Eliot (Connoisseur’s Guide to California Wine, May 2014).

“Minerality is a sense of mineral-ness in the wine, including flavors of slate, schist, silex, etc.” Wikipedia.

One of the most thorough scientific discussions of minerality appeared in the wine blog, ‘Wine-Mise en abyme’ (“Minerality in wine? Fuggedaboudit,” June 18, 2013) at www.mowse.blogspot.com/2013/06. This post summarized the work of Alex Maltman of the Institute of Geography and Earth Sciences, Aberystwyth University, Wales. Maltman has pointed out that the term ‘minerality‘ is a contemporary invention that has no basis in science-based tasting schemes. Maltman’s article that appeared in the Journal of Wine Research in 2013 is heavily quoted in this post. The amount of nutrient ions absorbed by the vine roots is not directly related to the amount of nutrient ions in the soil. Maltman notes, “The proportion of mineral nutrients in finished wine bears only a complex, indirect, and distant relationship with geological minerals in the vineyard.” Maltman argues that minerality cannot be tasted in wine. He further states that the concentration of inorganic material and mineral elements, in particular, in wine is minuscule, and these mineral elements have no flavor. Only sodium chloride among all the minerals produces a flavor in the mouth.

Scott first met with the issue of minerality in 1989 when he was Clark Smith’s research enologist at R.H. Phillips Vineyard. The job involved many vineyard-based and winery-based experiments. Many of the experimental results were validated using tasting panels and statistical methods to determine the significance in differences found among experimental treatments. In order for the tasting panels to have a common vocabulary, flavor and aroma standards were prepared so that all terms were clearly defined and all tasters knew precisely what each descriptive term meant. Scott told me, “One of the most interesting standards was for a Semillon that we felt possessed the aroma of wet granite after a rainstorm. I prepared a standard for this descriptor by pouring distilled water over a piece of granite, recovering the water, and repeating the process until the essence was noticeable in the water.

Scott has taken an early step in establishing standards for minerality descriptors. He sent me four minerality standards: Squaw Valley granite, Mt. Harlan limestone, Sonoma Mountain basalt, and Lodi gravel. They were prepared by crushing pieces of each rock and soaking them in a solution of 30% Sky vodka which is the most neutral as determined by a blind vodka tasting, and 70% distilled water for a couple of weeks. The solution was then filtered through a 0.45 micron disk filter with the solution delivered via syringe to remove any heavy metals or other toxins associated with the minerals. I only evaluated the aromas (blind) of the sample liquids and did not drink them. My impressions were similar to Scott’s:

Sonoma Mountain basalt: wet mud, wet terra cotta, wet clay, earth

Squaw Valley granite: very subtle steely, stainless steel impression

Lodi gravel: similar to Squaw Valley granite, primarily smelled like mineral water

Mt. Harlan limestone: distinctive aromas of cement, dirt, earth, clay and grass

Considering these preliminary results, Scott feels that there needs to be an expanded aroma wheel (an addition to Ann Noble’s aroma wheel) or a new one to address minerality, and he might begin work on the challenge.

Read Scott’s up close and personal feature at the end of this issue.

Postscript: Shortly after this article was published, an article appeared in The World of Fine Wine(Issue 45 2014, pp 128-136), titled "Between Rock And A Hard Place: Vineyard Soils," written by Alex Maltman. In this piece, he clarifies the bedrock geology of vineyards. To summarize, here is what he said. "The Earth is made of chemical elements and is dominated by just eight of them. Elements are combined with each other to form minerals. The vast majority of minerals making up vineyards are silicates. The rigid aggregates of minerals are properly called rocks. Minerals combine to make rock, and minerals are composed of chemical elements. When elements amalgamate they become crystalline. The pieces of minerals in a vineyard are crystalline. 17 or so mineral nutrients are needed for vine growth and some of these are needed in very different amounts. The word soil refers to mineral sediments mixed in with rotted biological material-humus." With regard to minerality in wine, Maltman states, "There would seem to be no basis for the common assertion that a particular kind of bedrock produces certain wine flavors....the connection between soil and wine may not be direct and literal, but a kinship exists."